/*
 * CPU kernel entry/exit control
 *
 * Copyright (C) 2013 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
#include <seminix/errno.h>
#include <seminix/of.h>
#include <seminix/string.h>
#include <asm/cpu_ops.h>

const struct cpu_operations *cpu_ops[CONFIG_NR_CPUS] __ro_after_init;

static const struct cpu_operations *const dt_supported_cpu_ops[] __initconst = {
    &smp_spin_table_ops,
    &cpu_psci_ops,
    NULL,
};

static const struct cpu_operations * __init cpu_get_ops(const char *name)
{
    const struct cpu_operations *const *ops;

    ops = dt_supported_cpu_ops;

    while (*ops) {
        if (!strcmp(name, (*ops)->name))
            return *ops;

        ops++;
    }

    return NULL;
}

static const char *__init cpu_read_enable_method(int cpu)
{
    const char *enable_method;
    struct device_node *dn = of_get_cpu_node(cpu, NULL);

    if (!dn) {
        if (!cpu)
            pr_err("Failed to find device node for boot cpu\n");
        return NULL;
    }

    enable_method = of_get_property(dn, "enable-method", NULL);
    if (!enable_method) {
        /*
            * The boot CPU may not have an enable method (e.g.
            * when spin-table is used for secondaries).
            * Don't warn spuriously.
            */
        if (cpu != 0)
            pr_err("%pOF: missing enable-method property\n",
                dn);
    }

    return enable_method;
}

/*
 * Read a cpu's enable method and record it in cpu_ops.
 */
int __init cpu_read_ops(int cpu)
{
    const char *enable_method = cpu_read_enable_method(cpu);

    if (!enable_method)
        return -ENODEV;

    cpu_ops[cpu] = cpu_get_ops(enable_method);
    if (!cpu_ops[cpu]) {
        pr_warn("Unsupported enable-method: %s\n", enable_method);
        return -EOPNOTSUPP;
    }

    return 0;
}
